ACS is the legacy cargo processing system that is transitioning to the Automated Commercial Environment (ACE). ACE is being developed as the primary, modernized system through which the U.S. Government will track, control and process all imported and exported goods.
As CBP processing is transitioned to ACE, the technical requirements for transmitting data to ACE will be posted on CBP.gov under the ACE webpage. The documentation for any functionality remaining in ACS will be posted here until that functionality transitions to ACE.
The ACS CATAIR documents are no longer being updated. If you cannot find the chapter that you are looking for on this page, an equivalent chapter may be available as an ACE CATAIR chapter. Functionality that is not transitioned to ACE and is no longer available in ACS will have the chapters removed from this page.